Apparatus for coating glass filaments

ABSTRACT

Apparatus for coating glass filaments with a liquid crosslinkable resin, which comprises a freely rotatable roller coater, guide means located upstream of the roller whereby the length of the arc of contact of the filaments with the roller surface may be varied, a combined wiper and recombiner for the coated filaments located downstream of the roller, and tensioning means for tensioning the filaments passing through the apparatus.

United States Patent [72] Inventor Robert Basier Sandemont, France [21] Appl. No. 807,685 [22] Filed Mar. 17, 1969 [45] Patented Feb. 2, 1971 [73] Assignee l-louilleres Du Bassin Du Nord & Du-De- Calais Douai, France a French public establishment [32] Priority Mar. 29, 1968 [33] France [31 146,476

[54] APPARATUS FOR COATING GLASS FILAMENTS 10 Claims, 2 Drawing Figs.

52 us. Cl 118/33, 118/122, 118/203, 118/246, 118/261 [51] Int. Cl. 1305C 1/04 [50] Field ofSearch 118/33,

[56] References Cited UNIT ED STATES PATENTS 1,288,641 12/1918 Mayer 118/246X 2,861,541 11/1958 Hornbostel 118/122X 3,323,298 6/1967 Marks et a1 l18/33X Primary Examiner-John P. McIntosh Attorney-Mam & Jangarathis ABSTRACT: Apparatus for coating glass filaments with a liquid cross-linkable resin, which comprises a freely rotatable roller coater, guide means located upstream of the roller whereby the length of the arc of contact of the filaments with the roller surface may be varied, a combined wiper and 'recombiner for the coated filaments located downstream of the roller, and tensioning means for tensioning the filaments passing through the apparatus.

PATENTED FEB 2197! APPARATUS FOR COATING GLASS FILAMENTS This invention is concerned with apparatus for coating glass filaments with a cross-linkable resin in liquid form.

It is known to coat glass filaments with cross-linkable resins, such as polyesters, polyepoxides and phenolic resins, and to form the coated filaments into hollow articles by winding the coated filaments on a rotating former of the appropriate shape and subsequently curing the resin.

Heretofore, the glass filaments have been coated with resin by passing them through a bath of the resin. in a typical arrangement, the glass filaments come off a bobbin carriage and, after being aligned by passage through a metal comb, go over a stationary steel support rod and then descend inclinedly into a tank containing the resin. The filaments pass round a stationary metal guide and tensioning rods at the bottom of the tank and ascend from the tank and pass to wiper rods and tensioning rods for removal of excess resin. Finally, the filaments go over a pivoted arm tensioner which adjusts the tension of the sheet or sliver of filaments to a constant value, whereafter the sliver passes to a rodding device before being wound on to the rotating former.

A system of this kind has many disadvantages. For instance, since the sheet of glass filaments rubs on metal combs and stationary metal rods and describes sharp bends in the tank, a relatively large number of filaments are broken during the operation; also, the filaments which are under heavy tension are unsatisfactorily coated with resin and carry a considerable excess of resin which drips on to the wiper rods.

We have now developed an improved apparatus for coating glass filaments with liquid resin which enables the breakage of filaments to be reduced and the coating of the filaments to be effected more satisfactorily.

According to the present invention, we provide apparatus for coating glass filaments with a cross-linkable resin in liquid form, which comprises a horizontally disposed, freely rotatable cylindrical roller, means for applying liquid resin to the surface of the roller so that, in use, glass filaments contacting the surface of the roller are coated with the resin, a first guide means located upstream of the roller for adjusting the path of the filaments passing to the roller whereby the length of the arc of contact of the filaments with the roller surface may be varied, a combined wiper and recombiner means disposed downstream of said roller and comprising a knife member having a planar convex rubber blade and a rigid member spaced from said blade and curved to conform to the curvature of said blade so that surplus liquid resin is wiped from the coated filaments passing between said blade and rigid member, and tensioning means for tensioning the filaments passing through the apparatus.

The first guide means preferably comprise a vertically adjustable tensioning jockey and the part of the latter that contacts the glass filaments is preferably formed of polyformal resin.

The apparatus preferably comprises a first comb arranged in the path of the filaments upstream of said first guide means,

a second comb arranged in the path of the filaments intermediate said roller and said combined wiper and recombiner means, and second guide means located intermediate a said roller and said second comb.

The cylindrical roller is preferably provided with a doctor blade having a micrometer adjustment, to adjust the thickness of the resin film on the roller, a gap of approximately 0.2-0.8 mm. being preferred, so as to reduce unnecessary carrying of an excess of the resin by the filaments. The roller is preferably provided also with a scraper to collect any lumps or pieces of filament accidentally deposited on the cylinder.

In order to gradually condense the sliver of coated glass filaments and gradually increase its thickness, the intertooth spacing of the second comb is preferably less than that of the first comb, and any comb further downstream has intertooth spacing less than the preceding upstream comb. The combined wiper and recombiner means removes excess resin carried along by the glass filament sliver and combines all the filaments into a single sheet which thus becomes condensed and thickened.

A preferred embodiment of the apparatus of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a diagrammatic elevation, partly in section, of the apparatus; and

FIG. 2 is a detailed plan view of the combined wiper and recombiner.

Referring to the drawings, the apparatus comprises an entry comb 1 having cylindrical sintered titanium oxide teeth la mounted on a compressed bakelised wood support, the comb serving to lay in one direction glass filaments 2 going from a bobbin carriage (not shown) towards a jockey 3 made of polyformal resin and disposed after the comb 1 and mounted on an arm 4 adjustably secured to a frame 5. The glass filaments then go over a stainless steel cylinder 6 adapted to rotate freely about its axis and partly immersed in a tank 7 containing cross-linkable resin 8. A steel doctor blade 9 with a micrometer adjustment, and a scraper comb 10 are provided. The device 9 serves to control the thickness of the resin film on cylinder 6 and the comb 10 serves to collect lumps of glass fibre deposited on the cylinder 6.

The impregnated filaments then go under a polished steel tensioning rod 11, through an intermediate comb 12 having sintered titanium oxide teeth, to a combined wiper and recombiner 13 comprising a steel knife having a planar convex blade 12a (see also FIG. 2) edged with rubber 13b and cooperating with a steel rod 13c which is curved at its center to intimately match the shape of the knife blade.

The impregnated glass filaments are then taken up on a pivoted arm tensioner 14 which is urged to apply tension by a resilient loading device 15 the tensioner 14 having tensioning and guide rollers 16-19 to adjust the tension of the sheet of impregnated filaments to a constant value. The filaments then pass to a rodding device 20 having a comb with polished steel teeth 20a and polished steel rods 20b, 20c.

In the embodiment shown in the drawings, the jockey 3 can be moved between two positions to provide an adjustment, of between approximately 5 and 30, of the angle over which the glass filaments engage with the cylinder 6. On either side of these values there is appreciable filament breakage. The use of combs having sintered titanium oxide teeth and of a smooth jockey of polyformal material is another means of reducing the breakage of untreated glass filaments. Also, limiting the thickness of resin film on the cylinder 6 to approximately 0.2- 0.8 mm. is an effective way of ensuring that the filaments do not carry an excess amount of resin.

The use of an entry comb 1 having 31 teeth at a 10 mm. spacing, of an intermediate comb 12 having 25 teeth at a 8 mm. spacing, of an exit comb 20a having 23 teeth at a 4 mm. spacing, and of a combined wiper and recombiner 13 whose convex portion has a radius of 270 mm. (approximately three times the width of the sheet of filaments) helps to gradually on condense the filaments of the sheet and gradually increase sheet thickness and ensure adequate coating of the filaments.

As an example, Norsodyne type 292 T, a tetrahydrophthalic polyester resin made by the Houilleres du Bassin du Nord et du Pas-de-Calais, having a 38.2 percent styrene content (viscosity: 3 poises at 25 C. and containing 2 percent (by weight) colloidal silica and 2 percent (by weight) paraffined styrene, was used as the cross-linkable resin. This resin was used to coat glass filaments in two forms of apparatus, one according to the invention and the other a conventional apparatus (control experiment) and the filaments were wound on aformer to make 3,000-litre capacity tanks. The results obtained are given in table I below:

TABLE I Comparative winding tests using a conventional coating apparatus and an apparatus according to the invention Conventional Apparatus according apparatus to the invention Glass filaments used... 23 reels of 64 ends 23 reels of 64 ends count: 2,360. count: 2,360. Maximum speed 17 m./min v 43 m./rnin. Tension (on coated 200 kg 570 kg.

sheet). Percent brcakages More than 40% (all 12% (function of glass grades). glass quahty) Breakages per 13,000 More than 0.5-1.

metre run. Percent glass in 60% maximum (no 80% constant and finished product. adjustment reproducible. ossible). Loss by run-ofi of resin 2 Output (length)/hour 17 m. 60 min. 23 43 60X23=59,340 m. reels= 23,460 In.

Theoretical weight 55.36 kg 140 kg.

delivered/hour.

Thus, the apparatus according to the invention enables the maximum sliver speed to be increased from 17 m./min. (conventional apparatus) to 43 m./min., i.e. by 2.5 times, sliver tension from 200 to 570 kg. (the output is practically prestressed material), the percentage of glass in the finished product from 60 percent to a constant and reproducible 80 percent, and the theoretical weight of glass filaments delivered per hour from 55 to 140 kg.

lclaim:

1. Apparatus for coating glass filaments with a cross-linkable resin in liquid form, which comprises a horizontally disposed, freely rotatable cylindrical roller, means for applying liquid resin to the surface of the roller so that, in use, glass filaments contacting the surface of the roller are coated with the resin, a first guide means located upstream of the roller for adjusting the path of the filaments passing to the roller whereby the length of the arc of contact of the filaments with the roller surface may be varied, a combined wiper and recombiner means disposed downstream of said roller and comprising a knife member having a planar convex rubber blade and a rigid member spaced from said blade and curved to conform to the curvature of said blade so that surplus liquid resin is wiped from the coated filaments passing between said blade and rigid member, and tensioning means for tensioning the filaments passing through the apparatus.

2. Apparatus according to claim 1, in which said first guide means comprise a vertically adjustable tensioning jockey.

3. Apparatus according to claim 2, in which that part of said tensioning jockey which contacts the filaments is formed of polyforrnal resin.

4. Apparatus according to claim 1, which comprises a first comb arranged in the path of the filaments upstream of said first guide means, a second comb arranged in the path of the filaments intermediate said roller and said combined wiper and recombiner means, and second guide means located intermediate said roller and said second comb.

5. Apparatus according to claim 4, in which said first comb has teeth formed of sintered titanium oxide.

6. Apparatus according to claim 4, in which the intertooth spacing of said first comb is more than that of said second comb.

7. Apparatus according to claim 1, in which said tensioning means comprise a pivoted arm tensioner arranged in the path of the filaments downstream of said combined wiper and recombiner means and rodding device carrying a third comb arranged in the path of the filaments downstream of said pivoted arm tensioner.

8. Apparatus according to claim 1, in which said first guide means is adapted to provide an arc of contact of the filaments with the roller surface of from 5 to 30.

9. Apparatus according to claim 1, in which said roller is provided with a doctor blade for controlling the thickness of the resin film on the roller surface after liquid resin has been applied thereto.

10. Apparatus according to claim 9, in which said roller is provided with a scraper for cleaning the roller surface prior to the application of liquid resin thereto. 

2. Apparatus according to claim 1, in which said first guide means comprise a vertically adjustable tensioning jockey.
 3. Apparatus according to claim 2, in which that part of said tensioning jockey which contacts the filaments is formed of polyformal resin.
 4. Apparatus according to claim 1, which comprises a first comb arranged in the path of the filaments upstream of said first guide means, a second comb arranged in the path of the filaments intermediate said roller and said combined wiper and recombiner means, and second guide means located intermediate said roller and said second comb.
 5. Apparatus according to claim 4, in which said first comb has teeth formed of sintered titanium oxide.
 6. Apparatus according to claim 4, in which the intertooth spacing of said first comb is more than that of said second comb.
 7. Apparatus according to claim 1, in which said tensioning means comprise a pivoted arm tensioner arranged in the path of the filaments downstream of said combined wiper and recombiner means and rodding device carrying a third comb arranged in the path of the filaments downstream of said pivoted arm tensioner.
 8. Apparatus according to claim 1, in which said first guide means is adapted to provide an arc of contact of the filaments with The roller surface of from 5* to 30*.
 9. Apparatus according to claim 1, in which said roller is provided with a doctor blade for controlling the thickness of the resin film on the roller surface after liquid resin has been applied thereto.
 10. Apparatus according to claim 9, in which said roller is provided with a scraper for cleaning the roller surface prior to the application of liquid resin thereto. 